Cooperative Adaptive Cruise Control (CACC) technology offers the prospect of a practical solution to increase road space utilization based on ad hoc, real-time cooperative driving allowing inter-vehicle distances to be safely reduced while improving the experience for drivers.

The Netherlands Organisation for Applied Scientific Research, TNO, is in the process of developing its own low cost and highly practical CACC technology. This is being demonstrated in a test fleet of Toyota Prius cars in which factory-fitted long-range radar is used together with wireless vehicle to vehicle communications (802.11p and ETSI Geonet) and GPS based location, to enable CACC. Control of each of the CACC equipped vehicles is achieved through interaction with the CAN bus in order to manage acceleration and deceleration directly through the hybrid powertrain’s own control system. The CACC control strategy aims to optimize the collective behaviour of participating vehicles in order to safely allow significant reductions in inter-vehicle spacing while providing a comfortable experience for drivers. This includes, for example, the avoidance of oscillations of the ad-hoc platoon and the management of issues of signal degradation and of merging in and out at junctions.

In order to test and demonstrate this advanced system and consider the potential for its further development, three of TNO’s Prius vehicles equipped with CACC were evaluated at innovITS ADVANCE in early March 2012. “We were pleased to be able to host these CACC tests,” commented innovITS ADVANCE business development manager Steven Warner. “With our private communications networks including GSM and WiFi systems and SkyClone GNSS system, we can model almost any urban scenario of signal attenuation, interruption or denial of service. As such innovITS ADVANCE is the ideal environment for the testing and development of this type of advanced cooperative vehicle technology.”